Microprints. A Pixel-Based, Semantically Rich Visualization Of Methods Romain Robbes, Stéphane Ducasse And Michele Lanza. ESUG 2005, Bruessels

1. Microprints
A Pixel-Based, Semantically Rich
Visualization Of Methods
Romain Robbes, Stéphane Ducasse
And Michele Lanza

2. Outline
• Visualization techniques
• Microprints
• Microprints at work
• Customizing Microprints
• Conclusion

3. Visualization
Techniques
And Some (Human) Limitations

4. Why Visualizing Code?
• A way to:
• Represent a lot of information in a
small space
• Choose starting points in an unknown
code base
• Facilitate code comprehension

5. Visualisation
Techniques
• Some examples:
• UML
• Syntax
Highlighting
• Polymetric Views

6. Limitations
• Visualizations are interpreted by
humans
• Unfortunately we are the limiting factor
• Limited color choice
• Limited information density

7. Limited Color Choice
• We must avoid:
• Colors too close to each other
• Too many colors (7 max)

8. Information Density
• Too much information renders it useless
• Harder to locate a precise information...
• Like finding a needle in a haystack

9. Microprints
Assumption, Principle and Advantages

10. Microprint Assumption
• It is easier to merge information than to
sort it
• It is easier to merge information than to
sort it
• It is easier to merge information than to
sort it
• It is easier to merge information than to
sort it

11. • So we reduce and stack each view:
It is easier to merge
information than to
sort it
It is easier to merge
information than to
sort it
But We Do Not Have
That Much Space!
It is easier to merge
information than to
sort it
It is easier to merge
information than to
sort it

12. Microprint Principle
• Several views of a method via a variant
of code highlighting:
• Variable access
• Control flow
• Object interactions
• Code and frequency coverage

13. Advantages of the
Approach
• Several focused views
• Few information in each view
• Few colors as well
• Colors can be reused in several views

14. Microprints at
Work
Sample Patterns, Alternative Uses

15. Microprints in Pictures

16. Sample Visual Patterns
• Lazy initialisation
• Complex/trivial
logic
• Template/
framework method

17. • Visualizing:
• Method protocols
• Classes
• Hierarchies
• Or more?
Alternative Uses of
Microprints

18. Customizing
Microprints
Roll Your Own Microprints in Two Easy
Lessons

19. First: Some
Implementation Details
• Microprints use the Refactoring Browser:
• RB parser, AST and visitor
• Microprint = color to marker mapping
• Markers = visitors of RB ASTs
• Looking for “interesting” nodes

20. Compose Your Own
Microprint
• Use the GUI to:
• Add markers
• Map them to
colors
• Set their priorities

21. Create Your Own
Marker
• Define a new visitor
• When an AST node is interesting:
• self mark: aNode (boolean)
• self mark: aNode value: v (integer)
• If you want to store a metric

22. Conclusion

23. Conclusion
• Merging information...
• Is easier than sorting it
• Microprints:
• Several semantic views of methods
• Integrated in VW and CodeCrawler
• Customizable and extensible

24. Any Questions?
• Here’s one:
• Which microprints would you need?